Dispensing containers for stick-type solid products are relatively abundant in the art. U.S. Pat. No. 2,980,246, which issued to J. Leshin on Apr. 18, 1961, for example, discloses a container-dispenser for solid stick products featuring a product follower constructed in a skeleton form in order to embed itself in the stick product when molded in the container. The Leshin patent contemplates pouring molten solid-stick product directly into the assembled container through its open upper end, with the molten material thereafter hardening to form the stick-solid product therein.
The art also shows stick-solid packages adapted to be filled in inverted condition via the bottom of the package. Such a package is disclosed in U.S. Pat. No. 4,369,158, which issued to Woodruff et al. on Jan. 18, 1983. In this patent, a stick antiperspirant package having generally open ends is fitted with a pouring cap mold on its upper end, and inverted for filling with molten product through its open bottom end. Immediately following the pouring of the molten material through the open bottom, a preassembled twist-up assembly is inserted therein. After solidification of the molten material, the pouring cap is removed and the upper end of the container is then covered by a separate cap. U.S. Pat. No. 4,298,036, which issued to William Horvath on Nov. 3, 1981, also shows a dispenser for stick solids which can be filled in the inverted position through its hollow base and stem structure. Horvath contemplates pouring molten product through its hollow central screw stem, while allowing air within the package to escape through vent holes formed in its plunger and base structures.
An oval cross-section stick-solid twist-up package is manufactured by Calumet Manufacturing Co. (East Orange, N.J.) and features a fully-assembled bottom fill design. The Calumet package comprises an oval shaped container body having a central aperture through a substantially closed bottom wall. A generally hollow screw knob is mounted on the exterior of the bottom wall and has a tubular internally threaded sleeve-like member which extends into the container body through the central aperture thereof. Mounted within the container body is a follower having a flat upper surface, a central bore, and an externally threaded tubular sleeve member which depends from adjacent the central bore and telescopes into the sleeve-like member of the screw knob for threaded interaction therewith. Rotational movement of the screw knob thereby axially displaces the follower within the container. A closure cap telescopes over the upper end of the container body thereby closing the package. Molten product is poured into the inverted assembled container through the hollow screw knob, through the sleeve members and through the central bore of the follower. Several vents are provided in the flat surface of the follower to allow escape of displaced air during the filling procedure. The telescoping sleeve members of the Calumet package, however, occupy a large portion of the package and prevent the follower from being fully retracted therewithin.
Despite all the prior work done in this area, as evidenced by the above-cited patents, there remain problems of manufacturing complexity, speed and efficiency, and excessive costs of such packages.